Determination of distribution and antibiotic susceptibility of nontuberculous mycobacteria (NTM) species in clinical samples from the cukurova region

Nontuberculous mycobacteria (NTM) cause serious infections especially in immunosuppressed patients by direct transmission from the environment or after colonization aruond the world. Difficulties in identification of these species from Mycobacterium tuberculosis complex may lead false diagnosis and treatments. In recent years, increased incidence of immunosuppressing diseases as Acquired Immunodeficiency Syndrome (AIDS) have further increased the prevalence and importance of nontuberculous mycobacteria (NTM) infections. Of the more than 140 NTM species reported in the literature, at least 25 species have been strongly associated with NTM diseases; the remainder are environmental organisms rarely encountered in clinical samples. The culturing and phenotypic identification of these bacteria at the species level is complex and time consuming. Therefore, nowadays molecular methods such as reverse hybridization, PCR-RFLP, DNA sequence analysis have gained importance. However, reasons such as great similarity of the genetic structure and identification of novel species and subspecies highly limit molecular diagnosis as well. Recent studies have exhibited, that sequence analysis of well protected gen regions such as hsp65, 16S rRNA, 16S–23S rRNA intergenic spacer region is more sensitive than phenotypic tests fort he species identification. The hsp65 gene, which is present in all mycobacteria, is more variable than the 16S rRNA gene sequence and is therefore potentially useful for the identification of genetically related species. The aim of this study to determine distribution and antibiotic susceptibility of TDM species in the Çukurova region. Also advantages and disadvantages of the methods will be examined. In this study, 96 NTM strains isolated from 21918 clinical materials of patients that have pulmoner tuberculosis and/or suspected contact from Adana and the neighboring provinces have been identified to species level by DNA sequence analysis method targeting the specific hsp65 gene region in the CU THAUM and Regional Laboratory for Tuberculosis from November 2012 to September 2014. Antibiotic resistance paterns have been evaluated by Lowenstein Jensen - Agar Proportion tests. It was observed that the most prevalent NTM isolate was M. abscessus with ratio of 24,7% (23/93), and antimicrobial resistance were frequently emerged against Doxycycline and Moxifloxacin with same ratio of 17,2% (16/93), whereas lowest resistance rate was detected against Clarithromycin as % 5,4 (5/93). In conclusion, considering the great number of the examined samples, besides determining the distribution and antibiotic susceptibility of NTM species in the Çukurova region, the movement of the known species in the population have been also monitored.